The present invention relates generally to intrusion detection systems and, more particularly, to a multilayered intrusion detection system and method.
Intrusion Detection was developed to extend security visibility into the network and monitor the activity of users while they are on the network. An Intrusion Detection System/Service (IDS) can augment an end-to-end security solution as a dynamic security component by detecting, responding to, and reporting unauthorized activity from data derived directly from the network.
Network intrusion detection is a process that can identify and respond to misuse or policy violations on a network. By placing sensing enabled devices at determined points on,the network, network traffic can be monitored and compared against patterns or xe2x80x9csignaturesxe2x80x9d that represent suspicious activity, misuse, or actual attacks. These devices can send alerts to the security management system and, under appropriate circumstances, send commands directly to network equipment such as routers and firewalls, reconfiguring them to deny access to the attacker. The system can automatically and quickly responds in a user-defined manner to send an alert or take immediate action.
Host-based intrusion detection monitors activity on a single system while network-based intrusion detection monitors all activity over a given network connection or segment. Host-based intrusion detection systems can be used to protect critical network servers or other individual systems containing sensitive information. The implementation of these systems is typically in the form of small clients or applications. Intrusions can be detected by analyzing operating system audit trails, application audit trails, and other system activity.
Network-based intrusion detection systems can be used to monitor activity on a specific network segment. Where a host-based intrusion detection system resides on a workstation and shares a CPU (central processing unit) with other user applications, a network-based solution is typically a dedicated platform. Conventional network-based intrusion detection systems can perform rule-based or expert system analysis of traffic using parameters set up by the security manager, and the signatures, which flag suspicious or attack activity. The systems can analyze network packet headers to make security decisions based on source, destination, and packet type. They can also analyze packet data to make decisions based on the actual data being transmitted. These systems scale well for network protection because the number of actual workstations, servers or user systems on the network is not critical. It is the amount of traffic which determines performance. In addition, sensing devices placed around the globe can be configured to report back to a central site, enabling a small team of security experts to support a large enterprise.
There are a variety of technical disadvantages associated with the aforementioned types of Intrusion Detection System/Service (IDS). For example, a host-based IDS cannot detect network wide intrusion attempts. Additionally, host-based systems require the use of a host server""s system resources such as disk space, RAM (random access memory), and CPU (central processing unit) time, and, as such, it impacts system performance. Host-based intrusion detection systems are ideal if a limited number of critical servers must be protected, however, they do not scale well if enterprise-wide solutions are needed. Alternatively, a network-based IDS might not have the processing power to detect all intrusion attempts on individual hosts.
In addition to the technical disadvantages observed by employing the above types of IDS, a series of other technical disadvantages exist in current IDS technology. As network bandwidth continues to increase, IDS""s are falling behind. It is possible that even if the IDS identifies an attack in a packet, a receiving host may have accepted the packet before the IDS has had an opportunity to act upon it. Additional technical disadvantages which occur from utilizing a network-based IDS include wasted processing resulting from the network-based IDS processing traffic which the host will discard without using as well as the network-based IDS""s inability to process encrypted traffic.
In accordance with the teachings of the present invention, a multilayered intrusion detection system and method is provided.
In one aspect, the present invention provides an intrusion detection method which maintains at least one registry indicating at least one host node capable of performing host-based intrusion detection services. The method also includes monitoring activity on a network and comparing at least one characteristic of the monitored activity with at least one host node in the registry. The network activity is dismissed when the monitored activity has at least one characteristic in common with at least one host node in the registry.
Another aspect of the present invention provides an intrusion detection method which includes monitoring activity on a network and maintains a registry of each host node address associated with a host node operable to perform host-based intrusion detection services. The method includes comparing a destination address of the monitored network activity with at least one host node address in the registry and dismissing the network activity having a destination address in common with at least one host node address in the registry. Intrusion detection services are performed on the network activity not dismissed to a registered host node by any of a plurality of network nodes and on the dismissed network activity using the host-based intrusion detection service operable on the host node receiving the dismissed network activity.
In yet another aspect, the present invention provides a computer system for use as an intrusion detection system including at least one processor and at least one computer readable medium communicatively coupled to the processor. A registry is stored on the computer readable medium, the registry operable to maintain entries indicative of at least one host node operable to perform intrusion detection services. The computer system is operable to dismiss network activity having a destination address indicative of at least one entry in the registry.
Another aspect of the present invention provides an intrusion detection system including at least one host node and at least one network node communicatively coupled to the host node including at least one processor and at least one computer readable medium communicatively coupled to the processor. A registry is stored on the computer readable medium, the registry operable to maintain entries indicative of at least one host node operable to perform intrusion detection services. The network node is operable to dismiss network activity having a destination address indicative of at least one host node entry in the registry.
In yet another aspect, the present invention provides a computer readable medium comprising at least one program operable to maintain at least one registry. The program is also operable to compare at least one characteristic of monitored network activity to at least one characteristic of the registry and to dismiss monitored network activity having at least one characteristic in common with at least one characteristic of the registry.
One technical advantage provided by the present invention is its ability to reduce the intrusion detection duties performed by network servers or other network appliances by performing intrusion detection duties at appropriately enabled hosts.
Another technical advantage provided by the present invention is its ability to perform intrusion detection monitoring on encrypted network traffic.
Yet another technical advantage provided by the present invention lies in its ability to prevent intruders, undetected by network intrusion detection services, from intruding host devices on the network by performing intrusion detection services at each registered host node.
An additional technical advantage provided by the present invention is its ability to allow a network intrusion detection system to perform primarily network-wide intrusion detection by enlisting hosts to perform host-based intrusion detection services.
Another technical advantage provided by the present invention is its ability to perform intrusion detection services on networks with more traffic than previously possible by sharing intrusion detection duties amongst network nodes and host nodes.
Another technical advantage provided by the present invention is its ability to provide comprehensive intrusion detection services on networks using tunneling services such as those utilized in virtual private networks (VPN).